As we get closer to winter, the phrase “atmospheric river” is more likely to pop up in headlines.
Here’s an explanation of what these phenomena are and how they impact weather in Northern California.
San Diego County has seen its fair share of storms over the last year, bringing historic levels of rainfall to the region.
After the driest three-year period on record, California has been battered by extensive precipitation, between a series of unrelenting atmospheric rivers that hit last winter and more recently, Tropical Storm Hilary.
An atmospheric river will bring significant rain to Northern California Monday and Tuesday but entirely miss San Diego County, which is days away from wrapping up an otherwise wet year, the National Weather Service said.
But there will be a slight chill to the air along the San Diego coastline — the kind that reminds people that it’s a good idea to keep a sweater handy. And you’ll need your winter wetsuit before long.
A moisture-rich atmospheric river that’s being called the first storm of the season is forecast to deliver rain to Northern California as early as Sunday night with the chance for showers continuing into Monday and Tuesday. Eureka and areas to the north are expected to see the heaviest rainfall with totals of 1 to 3 inches, while the Bay Area is likely to receive only light showers, according to the National Weather Service.
Atmospheric rivers are essential for the transportation of precipitation occurring in the Northern and Southern Hemisphere. The rapidly changing climate is causing shifts in these long, flowing regions of the atmosphere, resulting in an increasing number of extreme weather events that bring about destruction across the world.
Swaths of California still saturated by ruthless storms will get walloped by another atmospheric river, spawning fears of renewed flooding and forcing some residents to flee.
The state has already been hammered by at least 11 atmospheric rivers this season. An atmospheric river is like a fire hose that carries saturated air from the tropics to higher latitudes, dumping relentless rain or snow.
The rain brought into Santa Barbara County by an atmospheric river Tuesday turned out to be less that forecast, but it still totaled between about 1.4 and 2 inches in most areas, although there were some notable exceptions.
Damage was also less as a result, with only minor localized mud flows, flooded streets and a couple of downed trees reported as of Wednesday morning.
Many areas have seen upwards of two inches of rain. The rain has caused sinkholes in Scripps Ranch and Encinitas to grow even bigger.
California’s 11th atmospheric river left the storm-soaked state with a bang Wednesday, bringing flooded roadways, landslides and toppled trees to the southern part of the state as well as drought-busting rainfall that meant the end of water restrictions for nearly 7 million people.
California is no stranger to big swings between wet and dry weather. The “atmospheric river” storms that have battered the state this winter are part of a system that has long interrupted periods of drought with huge bursts of rain — indeed, they provide somewhere between 30 and 50 percent of all precipitation on the West Coast.
The parade of storms that has struck California in recent months has dropped more than 30 trillion gallons of water on the state, refilling reservoirs that had sat empty for years and burying mountain towns in snow.
The Water News Network is San Diego County’s source for water news and information.
